1. Field of the Invention
The present invention is directed to an orthotic brace and, more particularly, to an orthosis having modular component parts, such as a hip orthosis, that can address the postoperative treatment of a patient following hip arthoplatyies.
2. Description of Related Art
Orthotic management of hip joint compromise has been a challenge for orthopaedics, orthotists, and therapists when dealing with patients whose hip joints and their associated soft tissues, joint integrity, alignment, and bone and capsular components are compromised. A hip is a multidirectional joint capable of flexion, extension, internal and external rotation, adduction, and abduction. In addition to its mobility, the hip joint must absorb the force of fill weight-bearing and provide stability to the pelvis both for standing and for single support during gait. Additionally, during walking, while one hip is stabilized, the opposite leg must have the strength, range of motion, and structural integrity to advance.
The hip joint is a synovial ball and socket joint that consists of the articulation of the spherical head of the femur with the cup-like shape of the acetabulum. An acetabular labrum attaches to the bony rim of the acetabulum and cups around the head of the femur to hold it firmly in place. Various ligaments add strength to the articulation of the hip joint and a large number of muscles act on the hip joint. The gluteus medius is primarily associated with abduction. Anterior fibers assist with flexion and internal rotation. Posterior fibers assist with extension and external rotation. These muscle groups stabilize the pelvis during a single leg support.
Frequently, these muscle groups are compromised when surgical procedures are performed at the hip joint, especially during a hip replacement surgery. A significant problem that occurs when a hip joint has been compromised is dislocation of the hip joint. Thus, the femoral head can be driven out of the acetabulum. The hip is most susceptible to posterior dislocation when it is flexed past 90xc2x0, internally rotated and adducted. Examples of this action occur in every day living, such as sitting on a low chair and leaning forward while putting weight on the affected hip joint and internally rotating when coming to a standing position. Thus, common activities of daily living, specifically excessive hip flexion with loaded extremity and internal rotation on the affected side, can cause dislocation. Anterior dislocation also occurs when a hip is externally rotated, abducted, and flexed and if, for example, a knee is subject to a force, such as accidentally hitting an object. The neck of the femur or the greater trochanter levers the femur out of the acetabulum. To avoid these problems, an orthosis must be able to effectively control the limits of extension and rotation in a patient who has experienced an anterior dislocation.
The assignee of the present invention has provided orthoses to control extension and external rotation with a line of xe2x80x9cNEWPORT(copyright)xe2x80x9d hip system products.
See, for example, Team Management of Hip Revision Patients Using a Post-Op Hip Orthosis by Lima et al., Journal of Prosthetics and Orthotics, Vol. 6, No. 1, Winter/1994.
An example of an orthotic hip support can be found in U.S. Pat. No. 5,830,168, while a safety device to assist movement of a person can be found in U.S. Pat. No. 5,361,418. An orthopedic hip and leg abductor is disclosed in U.S. Pat. No. 5,361,418.
As the median age of the population becomes older, there are more occasions for the treatment of hip disorders and there is still a need to improve the function of such orthoses and their component parts in this medical field in an economical manner, while addressing a comfort level for the patient to encourage maximize prolonged usage.
The present invention is directed to a modular orthosis and to improvements in pre-fabricated component parts of the modular system for not only a hip orthosis, but for other broader applications in the orthotic field.
The orthosis can include a pelvic or hip engaging unit that is formed to conform to the contours of a human hip. This hip engaging unit can include multi-positional joints which can enable expansion, contraction, and rotation to permit a prefabrication of the hip engaging unit and a subsequent adjustment to the particular anatomy of the patient. The hip engaging unit can include first and second rigid outer hip engaging members with a relatively flexible rear connector plate adjustably interconnecting the first and second hip engaging members. A closure system can securely mount the hip engaging unit on the patient. The connector plate can have a bridge member extending vertically upward and across a hip band member to not only stiffen the connector plate from relative rotational movement, but also to provide a handle to permit an orthotist, a therapist or family care provider to assist in training the patient in the use of the orthosis.
An adjustable support plate assembly can be connected to an anchor location on the hip engaging unit. The support plate can have a securement portion adjacent the anchor location with a curved configuration to enable an adjustable movement of a distal end towards and away from the user. The distal end of the support plate can in turn be connected to an appendant orthotic member which can encircle and restrain movement of the leg of the patient.
Preferably, an adjustable hinge unit is provided to enable a range of both flexion and abduction movement. In one embodiment of the invention, an adjustable linkage system can extend across an articulated joint to permit a setting of a range of abduction that can vary with flexion. Flexion can be controlled with a variable setting hinge member. A link member that can be adjusted in length is pivotally affixed on either side of the articulated joint. The link member can be fixed at a location offset from a first rotational axis of the hinge member. The articulated joint has a second rotational axis which can be offset approximately 90xc2x0 from the first rotational axis of the hinge members whereby movement about the first rotational axis will cause movement of the articulated joint about the second rotational axis. Since the hinge member is adjustable to control the range of flexion and extension and the link member is adjustable to control adduction and abduction, a controlled compound motion is afforded the patient.
An alternative adjustable hinge unit can utilize a variable setting hinge member with a pivotal joint member connecting the hinge member to a bar that is attached to the appendant orthotic member. A follower roller and cam member can control the bar""s movement in adduction and abduction as the hinge member permits the hip joint to flex and extend.
The appendant orthotic member can be pre-fabricated in the form of a sleeve member or diagonal semi-rigid cylindrical band that can be adjusted in dimension to fit the thigh and knee portion of the patient. The sleeve member is formed of a relatively rigid plastic with a degree of flex and adjustable joints are provided for varying an encircling dimension of the sleeve member on the appendage to provide a custom fit for the user. Since the outer upper side of the sleeve member is longitudinally displaced from an opposite lower portion adjacent the knee, corresponding fixation points are provided to prevent rotational displacement of the sleeve member about the leg. Appropriate resilient pads can be removably fastened to both the hip engaging unit and the appendant sleeve member to directly bear against the patient""s body.